Case IH 56027 – Transmission Controller (TRANS): 2R Valve Coil circuit is shorted to 12 volts when the valve is ON.

The transmission controller has commanded the 2R clutch solenoid coil to turn ON, but it detects that the voltage on the low side of the coil is higher than expected. This indicates a short to 12V power in the circuit.

• STX Steiger
• Puma
• Magnum
• Steiger
• Maxxum
• Optum

1. 1

   Inspect the wiring harness between the 2R clutch solenoid and the transmission controller for chafing, melted insulation, or pinched wires indicating a short to a 12V power source

2. 2

   Test the 2R clutch solenoid coil for an internal short by checking its resistance against OEM specifications

3. 3

   Test the transmission controller for an internal failure if the wiring harness and solenoid coil both test good

1. 1

   Power Down

   Turn off the tractor and disconnect the battery to prevent accidental shorts during testing.

2. 2

   Locate Components

   Locate the transmission controller in the cab and the transmission control valve block on the side of the transmission housing. Identify the specific solenoid designated for the 2R clutch.

3. 3

   Check Wiring

   Disconnect the harness at both the 2R solenoid and the transmission controller. Use a multimeter to test the 2R circuit wire for continuity to any 12V power wires. If a short is found, repair or replace the damaged section of the wiring harness.

4. 4

   Check Solenoid

   If the wiring is intact, test the 2R solenoid coil for an internal short. If it fails the resistance test, replace the electro-valve coil.

5. 5

   Controller Replacement

   If both the wiring and the solenoid are in perfect working order, the fault lies within the transmission controller. Replace the transmission controller and perform the necessary transmission calibration procedures using the electronic service tool.

6. 6

   Clear Codes & Test

   Reconnect the battery, clear the fault codes, and shift the transmission through the forward and reverse gears to verify the repair. (Note: The manual states this fault is typically recorded when shifting into specific forward gears like 3, 9, 10, or 15 if the short is present).